package com.mashibing.juc.c_023_02_FromHashTableToCHM;

import java.util.HashMap;
import java.util.UUID;

/**
 * 只有一个线程时使用HashMap
 * @author: Yuanzt
 * @Date: 2021/4/1
 */
public class T02_TestHashMap {

    static HashMap<UUID,UUID> m = new HashMap<>();

    static int count = Constants.COUNT;
    static UUID[] keys = new UUID[count];
    static UUID[] values = new UUID[count];
    static final int THREAD_COUNT = Constants.THREAD_COUNT;

    static {
        for (int i = 0; i < count; i++) {
            keys[i] = UUID.randomUUID();
            values[i] = UUID.randomUUID();
        }
    }

    static class MyThread extends Thread{
        int start;
        int gap = count/THREAD_COUNT;

        public MyThread(int start){
            this.start = start;
        }

        @Override
        public void run(){
            for (int i = 0; i < start + gap; i++) {
                m.put(keys[i],values[i]);
            }
        }

        public static void main(String[] args) {
            long start = System.currentTimeMillis();

            Thread[] threads = new Thread[THREAD_COUNT];

            for (int i = 0; i < threads.length; i++) {
                threads[i] = new MyThread(i*(count/THREAD_COUNT));
            }

            for (Thread t : threads) {
                t.start();
            }

            for (Thread t : threads) {
                try {
                    t.join();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }

            long end = System.currentTimeMillis();
            System.out.println(end - start);
            System.out.println(m.size());
        }
    }

}
